/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package org.jboss.netty.util.internal;

import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;

/**
 * Warn when user creates too many instances to avoid {@link OutOfMemoryError}.
 */
public class SharedResourceMisuseDetector {

    private static final int MAX_ACTIVE_INSTANCES = 256;

    private final AtomicLong activeInstances = new AtomicLong();
    private final AtomicBoolean logged = new AtomicBoolean();

    public SharedResourceMisuseDetector() {
    }

    public void increase() {
        if (activeInstances.incrementAndGet() > MAX_ACTIVE_INSTANCES) {
        	logged.compareAndSet(false, true);
        }
    }

    public void decrease() {
        activeInstances.decrementAndGet();
    }
}
